A DAC is mostly made up of semiconductors and solid state components. The likelihood of any failure is slim. If it's going to break, it will do so out of the box. The brands you have chosen are all good, so go with the one that sound the best to you.
Company headquarters and warranty repairs
I'm contemplating between three DACs: Ayre QX5 Twenty, Chord Dave, and Mola Mola Tambaqui. I've not yet auditioned them but will do so in the next few weeks.
These companies are in the US, UK, and Netherlands respectively. If I buy a DAC and I need to send it in for a repair/upgrade, being able to send it to a center in the same country as I live in (US) would be cheaper and faster. If I was considering cheaper DACs (e.g., < $1000) I may not care but with a $10+K DAC, if it breaks down even in a few years, I *will* want to get it repaired.
Any thoughts on the reliability of these DACs (and thus the likelihood that I'd need to send them in). Is this something you consider or should I just worry about sound quality since it is unlikely that an electronic component with no moving parts will need a repair?